Transient frequency response of transmittance-peaked i.f. filters with application to null-zone detection

A binary f.s.k. system, where the i.f. filter has transmittance peaks at two frequencies separated by a large distance in comparison to the bit rate, is considered. Experimental confirmation of the system transient response when the filters are third-order Butterworth is presented. A brief discussion of the error probability of such a system, and a possible application of the nature of the transient response to allow null-zone detection, is given.